Should I buy a new HU??

I have an alpine 9833 and the KCA420i ipod adapter and that is great. It is a little slow but I don't mind it. This deck has been an excellent deck bought it new in 2004. I have been thinking about buying a new one though. I don't even know what. The only alpine I like is the idax001. I bought a new car and just am thinking about changing. I don't need to but kinda want to. What should I look at under $300.